I ask myself this question often and I'm not sure why really, I suppose its just habit.
I think it also has something to do with how everyone believes they can be a project manager. That it would be easy to do if I done it day in day out. All it is about is being organised and making a plan. To me many don't understand what we have to go through.
For instance you ask a member of the public to plan out how they will get from Point A to Point C they will start at Point A and work their way forward. Whereas a Project manager will look at Point A start at Point C and then work their way backwards.
Also there are many thing experienced managers will know more than complete newbies also know as tricks of the trade. These might include understanding the difference of sticking to the plan. Allowing time if things over run. And most importantly what to do if things do not run to plan.
This is very much speculation on my part. Making statements that all project managers work in the same way.
For example would a construction project manager be able to cope working as a project manager for a training company? What I mean is can a project manager from one industry have the ability to work in a totally different industry or sector and be able to do a good job at it?
Are the skills transferable or is the knowledge industry relayed and nothing to do with the project managers industry what so ever.
Maybe project manager community just provide the basic tools to use and then its up to the individual manager to work out how best to apply it to their industry.
Its funny how I start my blog post starting with one question and I end up having more questions by the end of it?
Let me know what you think?